Heart Disease Health Center

5 Heart Rate Myths Debunked

Myth #4: A slow heart rate means a weak heart.

"People often think that if their resting heart rate is too slow, they are on the precipice of having their heart stop completely," Tomaselli says. In fact, it tends to be just the opposite.

The heart is a muscle, and, like all muscles, it grows stronger with exercise. The stronger it is, the more efficient it is, taking fewer beats to pump blood throughout the body. So a heart with a resting heart rate under 50 (a condition known as bradycardia) is likely to be especially strong and healthy. That’s why highly conditioned athletes often have resting heart rates of 40 to 60 beats per minute. Famously fit bicycle racer Lance Armstrong, for example, reportedly has a resting heart rate of 32. (For more information on heart rate and fitness, read "The Truth About Heart Rate and Exercise.")

"In general, a slow heart rate that is [not causing any symptoms] is not cause for concern," Marine says. This is particularly true in younger individuals.

In the elderly, bradycardia (even if asymptomatic) might actually signal that heart disease is present. Certain medications, including beta-blockers and other heart drugs, can also cause bradycardia.  Bradycardia symptoms may include fatigue, dizziness, and fainting.

Myth #5: Since my heart rate is normal, my blood pressure must be normal too.

There's no simple relationship between heart rate (which is measured in beats per minute) and blood pressure (measured in millimeters of mercury, or mmHg).

A person can have a normal resting heart rate and still have high blood pressure. And someone whose heart rate is abnormal can have normal blood pressure. Strenuous exertion sharply raises heart rate, but it may only modestly increase blood pressure.  

The bottom line? Heart rate and blood pressure are not the same. The only way to know your blood pressure is to measure it with a blood pressure cuff.